PREDICTION OF HEARING-AID BENEFIT - THE ROLE OF PREFERRED LISTENING LEVELS

The listening level chosen by a hearing aid wearer for receiving ampli fied speech in noise has a substantial impact on the benefit that the hearing aid can provide. Chosen listening levels determine (1) the ext ent to which audibility of speech cues is improved by amplification, ( 2) the in situ distortion generated by the hearing aid, and sometimes (3) the auditory resolution abilities available to the hearing-impaire d listener. All of these variables have been shown to affect hearing a id benefit. Thus, to predict benefit in any particular listening envir onment, the listening level that the wearer would choose in that setti ng must be known with some precision. This paper reports two studies o f chosen, or preferred, listening levels. We present evidence to show that preferred listening levels vary with changes in the listening env ironment, especially when the signal-to-noise ratio is favorable. We d escribe a method for predicting preferred listening level changes in s ome environments that differ in talker levels and/or signal-to-noise r atios.